This invention relates to snow removal, particularly by snowblowers in which propeller drums are mounted on centrally driven support axles.
Such a "drum" snowblower, which typically is provided with two drums, is illustratively described in German Pat. No. 2,147,001. The clearing width of a drum snowblower is typically in the range from two to three meters when two drums are used. Generally a separate ejection chimney is associated with each drum. Snow taken up by a drum is then freely ejected through a corresponding ejection chimney, or is conveyed to a loading surface, such as that of a truck.
When snow accumulates in banks, such as in city areas, another type of snowblower has been found to be advantageous. This is the "lateral" blower which has a clearing width formed in part by a propeller drum and in part by a feed-in plow. The plow is disposed at a slant, with an outer edge in the clearing direction before an inner edge adjacent to the drum. The feed-in plow conveys snow from the side to the front of the drum which disposes of both the conveyed and the frontal snow.
In many cases it is desirable to use a snowblower for both the removal of snowbanks and surface clearing of roads and parking lots. The lateral snowblower has limited suitability for surface cleaning. Because of its feed-in plow, the lateral blower tends to stick in snow which is heavy or has substantial accumulation.
The double drum snowblower, on the other hand, is inefficient for the removal of snowbanks. This is because the propeller drum next to a snowbank rotates without being in contact with the snow. Not only is there a resultant waste of energy, there also is an appreciable risk that the ejection chimney of the unloaded drum will become clogged. This is because there is little or no conveyance of snow so that the ejection rate of the snow is correspondingly low. When an ejection chimney becomes clogged, which can occur frequently in the presence of snowbanks, the clearing operation must be interrupted to permit unclogging. In addition, the unloaded drum which is in continuous rotation presents a hazard to passersby.
Accordingly, it is an object of the invention to facilitate the removal of snow. A related object is to achieve efficient snow removal for both the clearing of snowbanks and surface areas.
Another object of the invention is to overcome the disadvantages and inefficiencies associated with lateral snowblowers in the clearing of surface areas. A related object is to achieve the efficient clearing of snow which has been deposited on surfaces in appreciable levels, or which has become compacted and is difficult to move.
Still another object of the invention is to overcome the disadvantages associated with drum snowblowers. A related object is to avoid the chimney clogging that often occurs when such a snowblower is used to clear snowbanks. Another related object is to avoid hazards to passersby from rotating propeller drums.